Development of CO2 absorption evaluating device for building materials

Quantitative analysis, such as thermogravimetric analysis (TGA), is often used to evaluate the CO2 absorption of building materials. However, as interest in CO2 absorption of building materials increases, a more universal and practical evaluation method has been required. This paper explains the mechanism of the "simple and visible" CO2 absorption evaluation device produced by the authors as a prototype and reports the CO2 absorption evaluation method and results. Experiments using the device showed that the higher the water-to-cement ratio and the larger the specific surface area of the hardened cement paste, the higher the CO2 absorption rate. Compared to the TGA results, a slight error occurred, which appeared to be due to an increase in vapor pressure due to H2O generated through the carbonation reaction. The device is useful when it is difficult to use expensive equipment because quantitative evaluation is possible if basic physical information is known in advance.